New model Hyundai's are shown on display at a Hyundai dealership in Burlingame, Calif., / Paul Sakuma AP

by Chris Woodyard, USA TODAY

by Chris Woodyard, USA TODAY

Buyer interest in new Hyundai and Kia vehicles may be softening following the South Korean automaker's admission that it inflated its gas mileage on several models, data from auto research website Edmunds.com indicate.

The website's finding is based on what it considers to be people logging onto the site with "purchase intent" for specific models in the past three months. It says purchase intent is "a metric for measuring a model's share of consumer demand."

Of 23 Hyundai and Kia models and variants, only three, Hyundai's premium Equus, Genesis sedan and coupe, showed an increase in buyer purchase intent from Sept. 2 to Nov. 18. All the others took a hit to varying degrees. For instance, Hyundai's popular compact sedan, the Elantra, saw its intent fall from 8% to 6.3%, according to the data provided to USA TODAY. Kia's popular Soul hatchback, which saw the biggest gas mileage reduction of any Hyundai or Kia model with up to 4 miles per gallon in combined city and highway driving, had buyer interest drop from 9.4% to 7.3%.

Even models that did not have their gas mileage ratings revised under pressure from the Environmental Protection Agency were affected. Kia Optima, for instance, saw a reduction from 6.9% to 5.3%.

Bill Visnic, a senior editor at Edmunds.com, told the Reuters news agency that given how "Hyundai, in particular, has made a media and consumer 'talking point' of the number of 40-miles-per-gallon vehicles it sells...this development has been considerably embarrassing,"

Hyundai and Kia blamed miscalculations and "human error" for the mistakes that led to gas mileage ratings. The EPA said it was the first time that an automaker has had to make such a large-scale revision. Hyundai and Kia initiated programs to reimburse owners for the difference between the old and new fuel-economy ratings based on the number of miles driven.

So far, the inflated gas-mileage figures have attracted at least three lawsuits seeking class-action status.